SOLUTION: Filling a tank. Two pipes are connected to the same tank. Working together, they can fill the tank in 4 hr. The larger pipe, working alone, can fill the tank in 6 hr less time than

Algebra.Com
Question 551226: Filling a tank. Two pipes are connected to the same tank. Working together, they can fill the tank in 4 hr. The larger pipe, working alone, can fill the tank in 6 hr less time than the smaller one. How long would the smaller one take, working alone, to fill the tank?
Answer by nerdybill(7384)   (Show Source): You can put this solution on YOUR website!
Filling a tank. Two pipes are connected to the same tank. Working together, they can fill the tank in 4 hr. The larger pipe, working alone, can fill the tank in 6 hr less time than the smaller one. How long would the smaller one take, working alone, to fill the tank?
.
Let x = time (hours) it takes for smaller one alone
then
x-6 = time (hours) it takes for larger one alone
.
4(1/x + 1/(x-6)) = 1
multiplying both sides by x(x-6):
4((x-6) + x) = x(x-6)
4(2x-6) = x^2-6x
8x-24 = x^2-6x
-24 = x^2-14x
0 = x^2-14x+24
0 = (x-2)(x-12)
x = {2,12}
throw out the 2 (extraneous) because it doesn't make sense leaving:
x = 12 hours

RELATED QUESTIONS

Two pipes are connected to the same tank. Working together, they can fill the tank in 4... (answered by scott8148)
Two Pipes are connected to the same tank. When working together, they can fill the tank... (answered by stanbon)
Two pipes are connected to a tank. When working together, the two pipes can fill the... (answered by ankor@dixie-net.com)
two pipes are used to fill a water tank. the smaller pipe can fill the water tank in 14... (answered by ikleyn)
Pipe A can fill a tank in 4 hr, Pipe B in 10 hrs and pipe C in 12 hrs. The pipes are... (answered by scott8148)
A small pipe can fill an oil tank in 6 min more time than it takes a larger pipe to fill... (answered by josmiceli)
A small pipe can fill a tank in 8 min more time than it takes a larger pipe to fill the... (answered by ikleyn)
A small pipe can fill a tank in 8 min more time than it takes a larger pipe to fill the... (answered by ankor@dixie-net.com)
Two water pipes can fill a tank with water in 6 hours. The larger pipe working alone can (answered by stanbon)